Download Chapter # 7 Skin Structure And Growth

Chapter # 7 Skin Structure
and Growth
Why do we need to know this?
• No matter how advanced the latest skin
care technology may be, knowing how to
care for skin begins with understanding its
underlying structure and basic needs. As
a licensed service provider, you must
recognize adverse conditions, including
inflamed skin conditions, diseases, and
infectious skin disorders
Basic Key Terms
• Dermatology is the medical branch of
science that deals with the study of skin, its
nature, structure, functions, diseases, and
treatments
• Dermatologist is the physician engaged in
the science of treating the skin
• Esthetician is a specialist in the cleansing,
preservation of health, and beautification of
the skin and body
Key Facts
• The skin is the largest organ of the body
• The skin of a typical 150 pound male weighs
about 9 lbs
• Our skin protects the muscles, bones, nerves,
and everything else inside our bodies against the
environment
• Healthy skin is slightly moist, soft and flexible
with a texture that is ideally smooth and fine
grained
• Healthy skin is slightly acidic 4.5-5.5 pH
Key Fact Continued
• Appendages of the skin are hair, nails, sweat, &
oil glands
• Eyelids are the thinnest skin
• Sole of our feet have the thickest skin
• Continued pressure on any part of the skin can
cause it to thicken and develop into a callus
• The scalp has larger and deeper hair follicles to
accommodate the longer hair of the head
Two Main Divisions of the Skin
Epidermis & Dermis
• Epidermis – outermost
layer of the skin, also called
the cuticle, contains no
blood vessels but has many
small nerve endings, made
up of 5 layers
• Dermis – underlying or inner layer of
skin also called the cutis, corium or
true skin. Highly sensitive layer of
connective tissue, 25 times thicker
than the epidermis, contains blood
vessels, nerves, sweat & oil glands,
lymph vessels, hair follicles, and the
arrector pili muscle. It is made up of 2
layers
7
7
Epidermis & Dermis
Epidermis Layers
•
•
•
•
•
Stratum Germinativum (basal cell layer)
Stratum Spinosum
Stratum Granulosum
Stratum Lucidum
Stratum Corneum
Stratum Germinativum
• Also called the basal cell layer
• Deepest layer of the epidermis
• Composed of several layers of differently
shaped cells
• It is the live layer that produces new
epidermal skin cells and is responsible for
the growth of the epidermis
Stratum Spinosum
• Spiny layer
• Just above the basal cell layer
• Beginning of the process that causes skin
cells to shed
Stratum Granulosum
• Granular layer
• Consists of cells that look like distinct
granules
• These cells are almost dead and are
pushed to the surface to replace cells that
are shed from the skin surface layer
Stratum Lucidum
• Clear transparent layer
• Just under the skin surface
• Consists of small cells through which light
can pass
Stratum Corneum
• Horny layer
• Outer layer of the epidermis
• The layer that we see when we look at the
skin
• The layer that can be treated by an
esthetician
• Its scale like cells are continually being
shed and replaced by cells coming to the
surface from underneath
Skin Cells
• Skin cells are made up of KERATIN which
is a fiber protein that is also the principal
component of hair and nails.
• The cells combine with lipids or fats
produced by the skin to help make the
stratum corneum a protective, waterproof
layer
Dermis
• Papillary Layer
• Reticular Layer
• Subcutaneous
Tissue
Papillary Layer
• Outer layer of the dermis directly beneath
the epidermis
• Here your will find the dermal papillae, hair
follicles, capillaries, pigment producing
cells, and tactile corpuscles
Reticular Layer
• Is the deeper layer of the dermis that
supplies the skin with oxygen and nutrients
• It contains the following structures within
its network: fat cells, sweat glands, blood
vessels, hair follicles, lymph vessels,
arrector pili muscle, and oil glands
Subcutaneous Tissue
• Also called adipose or subcutis
• Is the fatty layer found below the dermis
• Varies in thickness according to the age, gender,
and general health of the individual
• It gives smoothness and contour to the body
• It contains fats for use as energy and also acts
as a protective cushion for the outer skin
How is Skin Nourished
• Blood supplies nutrients and oxygen to the
skin
• Lymph bathe the skin cells and remove
toxins and cellular waste and have immune
functions that help protect the skin against
disease
Nerves of the Skin / Sense of
Touch
• The skin contains motor nerve fibers,
sensory nerve fibers, and sectetory nerve
fibers
• Nerve endings are most abundant in the
fingertips
• All of the nerve endings that provide the
body with the sense of touch are housed in
the papillary layer of the dermis
Skin Color
• Depends primarily on Melanin
• Melanin is the tiny grains of pigment located in
the basal cell layer of the epidermis and the
papillary layer of the dermis
• Color of skin is a hereditary trait and varies
among races and nationalities
• The body produces 2 types of melanin
Pheomelanin which is red / yellow and
Eumelanin which is Dark Brown to Black
Strength and Flexibility of the Skin
• The skin gets its strength, form, and
flexibility from two specific structures which
make up 70% of the dermis
• Collagen
• Elastin
Collagen
• A fibrous protein that gives the skin form and strength
• Makes up a large portion of the dermis and gives
structural support to the skin by holding together all the
structures found in this layer
• When healthy they allow the skin to stretch and contract
as necessary
• If they become weakened due to lack of moisture in the
skin, or environmental damage the skin will begin to lose
its tone and suppleness
• Wrinkles and sagging are of the result of collagen fibers
losing their strength
Elastin
• A protein base similar to collagen that
forms elastic tissue
• Gives skin its flexibility and elasticity
• Helps the skin regain its shape even after
being repeatedly stretched or expanded
Glands of the Skin
Sudoriferous & Sebaceous
Sudoriferous Glands
• Sweat glands excrete sweat from the skin
• They have a tube-like duct that ends at the skin surface
to form the sweat pore
• Located on almost all parts of the body but are more
numerous on the palms, soles, forehead, and armpits
• They regulate body temperature. Their activity is
increased by heat, exercise, emotions, and certain drugs
• The excretion of sweat is controlled by the nervous
system
Glands of the Skin
Sudoriferous & Sebaceous
Sebaceous
• Oil glands
• Are connected to the hair follicles
• Consist of little sacs with ducts that open into the follicles
• These glands secrete sebum, a fatty or oil secretion that
lubricates the skin and preserves the softness of the hair
• These glands are found on all parts of the body except
the palms and soles
• When sebum hardens and the duct becomes clogged a
comedone is formed which usually leads to a papule or
pustule more commonly known as a pimple
Functions of the Skin
• Protection – from injury and bacterial invasions
• Sensation – when the nerve endings are stimulated a
message is sent to the brain
• Heat Regulation – normal constant internal temperature
is about 98.6
• Excretion – perspiration, cleansing of the body
• Secretion – sebum or oil to lubricate the skin
• Absorption – is limited but does occur, ingredients such
as those in advanced skin care formulations may be
absorbed between the cells and through the hair follicles
and sebaceous gland openings
Maintaining Skin Health
• You are what you eat still holds true,
proper diet choices help to regulate
hydration, oil production, and overall
function of the cells
• Vitamins play an important role in the
skin’s health
Vitamins
• Vitamin A – supports overall health of the skin,
antioxidant which helps slow the process of aging and
prevents certain cancers, often used to treat acne as
Retin-A
• Vitamin C – needed for proper repair of the skin and
various tissues, this vitamin speeds up healing process,
also key in the production of collagen which is useful for
antiaging
• Vitamin D – rapid healing of skin, the best source of this
vitamin is sunlight in limited amounts (with sunscreen) it
can also be obtained from Milk and OJ, helps support
bone structure
• Vitamin E – used with vitamin A helps fight against the
harmful effects of the sun’s rays, heals damage to skins
tissue, when used in a lotion helps heal sunburn and
stretch marks
WATER
• There is one essential nutrient that no person
can live without that that is WATER
• The skin in order to function properly relies
heavily upon water
• Water composes 50-70% of our body weight
• Drinking pure water is essential to the health of
the skin and the body because it sustains the
health of the cells, aids in the elimination of
toxins and waste, regulates the body’s
temperature and aids in proper digestion
How much water each
day?
• Take your body weight divide by 16
• The result is the number of 8 ounce
glasses that you should drink everyday
• If you take part in intense physical activity
add two extra glasses of water, that will
help replace the extra fluids that are lost
while exercising